Dental flask.



No. 644,970. Patented Mar. 6, I900.

T. G. DUNALDSUN.

DENTAL FLASK.

(Application filed Feb. 6 1899.) No Model.)

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ATTORNEY THE Nonms PETERS on. PHu'm-Lmm. wnsnwmm u. r..

UNTTED STATES PATENT @FFICE.

THOMAS GRAHAM DONALDSON, OF BALTIMORE, MARYLAND.

DENTAL FLAS K.

SPECIFICATION forming part of Letters Patent No. 644,970, dated March 6,1900. Application filed February 6, 1899. $erial No. 704,731- (Nomodel.)

T 0 all whom it may concern:

Be it known that I, THOMAS GRAHAM DON- ALDSON, a citizen of the UnitedStates, residing in the city of Baltimore, State of Maryland, haveinvented certain new and useful Improvements in Dental Flasks, of whichthe following is a specification.

My invention relates to improvements in dental flasks; and the objectsof my improvements are, first, to provide for the use of dentists avulcanizing-flask combined with greater strength, durability, andsimplicity and one that can be adjusted and taken apart more easily andin shorter time than dental flasks now in use; second, to dispenseentirely with bolts and to avoid the necessity or need of a presstoolose or fasten the flask, and, third, to provide for equal pressureon all parts of the flask. I attain these objects by the mechanismillustrated in the accompanying drawings, in which- Figure 1 is avertical section through the flask on line A B. Fig. 2 is a top planview of the bottom section. Fig. 3 is a top plan view of the middlesection. Fig. 4 is a top plan view of my flask-holder. Fig. 5 is a topplan view of the equalizing compressor-plate. Fig. 6 is a top plan viewof the top section. Fig. 7 is a view in elevation of one of the threelinks. Fig. 8 is a diminished view of the wrench.

Similar numerals and letters refer to similar parts throughout theseveral views.

The flask is composed of a top section 4, a middle section 3, and abottom section 2, in which the middle section 3 and the bottom section 2are detachably connected together by two pin-and-hole connections 9 10,one on each side of the flask, the pins 9 being securely attached to themiddle section 3,which fit into holes 10 in the bottom section 2. Thesections of the flask when compressed or onbeing compressed are alsoheld'the more securely by the three links, like the one shown in Fig. 7,passing through the slots 11, 12, 13, and 14.

To compress the flask, I use the flask-holder 1, (shown in Fig. 4,)which is secured to a relatively-permanent part, such as a dentiststable a, a fragment of which is shown in the of the linksto pass underthe lugs of the bot- I tom section. The flask holder is also providedwith recesses a which receive the an .gular portions of the bottomsection to pre-' vent rotary motion.

The equalizing compressor-plate 5 is provided with one equalizingcompressor-screw 7, having a socket 18 for receiving the wrench 20, bywhich when the links, Fig. 7, are adj usted, as aforesaid, theequalizing compressor-screw 7 may be turned so as to press uponthecountersink 19 in the top section 4, forcing down the top section 4tagainst the mid dle section 3 and the middle section 3 against thebottom section 2, and thus compressing the flask.

The equalizing compressor-plate 5 is made, preferably, of gun-metal,very tough and capa* ble of standing great resistance,and theequal-' izing compressor-screw 7 is so arranged that on being turned bythe wrench 20, Fig. 8, is capable of exerting much greater pressure uponthe flask than any other character of screw or by screw bolts and nutsas are some times used, is more easily and in shorter time manipulated,-is more powerful than neces sary, and dispenses entirely with thenecessity or need of a press to close or fasten it.

I am aware that prior to my invention vul= canizing flasks for the useof dentists have been made with a compressor comprising a top, a bottom,and connecting ends, said top being provided with one or morescrew-plugs having a portion adapted for receiving a wrench and capableof being screwed down below the upper face of the top of'the compressor.I therefore do not claim such a 001m bination, broadly; but

What I do claim as my invention, and desire to secure by Letters Patent,is

1. The combination with a dental flask of an equalizing compressor-plate provided with an equalizing compressor-screw andconnecting-links securable to the bottom section of said flasksubstantially as described.

2. The combination in a dental flask comprising a flask-holder, anequalizing compressor-plate, flask-sections, and connectinglinks withmeans for compressing said flasksections, substantially as described.

3. An equalizing compressor-plate for compressing the dental flask,provided with an equalizing compressor-screw having a socket forreceiving the wrench, said equalizing compressor plate being alsoprovided with grooved lugs for receiving securing-links, and means fortightening the flask parts, substantially as described.

4. The combination in a dental flask comprising a flask-holder, awrench, an equalizing compressor-plate provided with an equal- .izingcompressor-screw and grooved for receiving the upper jaws of the links,and links with means for connecting and tightening the parts of theflask, substantially as described. 7 5. The combination of a dentalflask with a compressor comprising a flask holder, a wrench, anequalizing compressor-plate, a top section, a middle section, a bottomsection, and connecting-links, the said equalizin g compressor-platebeing provided with equalizing compressor-screw with socket forreceiving the wrench and with grooved lugs for receiving the upper jawsof the connecting-links; and the said bottom section being provided withl ugs for receiving the enlarged lower ends of the links, forcompressing and tightening the flask-sections, substantially asdescribed.

In testimony whereof I have signed my name to this specification, this3d day of February, 1899, in the presence of two subscribing witnesses.

THOMAS GRAHAM DONALDSON. Witnesses:

ABRAHAM H. FISHER, JOHN P. WAGNER.

